SE/30 Very Unusual Screen Artifacts

I had my SE/30 up and running (with TS adapter and Daystar Turbo 040) for about 15 minutes today when I head a little "beep" sound from the analog board (I think) and then the machine froze. I rebooted and it started to load off the hard drive when I heard that little sound again and the machine froze. Whenever I heard the sound, I also saw a very very quick hiccup on the screen, like a little vertical spike toward the middle of the screen. It only flashed on for something like 10ms to my eye, so it could hardly been seen, but I spotted it at the same time I heard the beep sound.

Anyway, after turning the machine on and off a few times and seeing it would only freeze, I opened the machine, disconnected the internal hard drive and Turbo 040 and TS adapter and powered on. This time I got the "chimes of death" and saw some unusual artifacts on the screen as shown in my attached photo.

I then pulled the motherboard and couldn't see anything wrong with it. This has been a known good and working SE/30 board for me for some time now. I had replaced all the capacitors (mostly with tantalums) to ensure good operation. For good measure I pulled out the RAM SIMMs and the ROM SIMM and replaced them. Upon booting I still got the artifacts. I get the artifacts even when I have the floppy drive disconnected. I then pulled the motherboard again and put a different ROM SIMM in (I had a IIsi ROM in there, but I put back in the stock SE/30 ROM). Still get the artifacts. I tried different RAM. Still get the artifacts (and chimes of death).

I next pulled another good working SE/30 motherboard (which I also re-capped) and had served me well a long time. It had a different ROM SIMM and RAM from my other motherboard. When I connected it and switched on power, there was no chime at all and I saw horizontal stripes (SimasiMac). I pulled the board an reseated the ROM and RAM. Still no sound and horizontal stripes. I then pulled the board and tried different RAM (never before used) and yet another ROM (I have several). Still get no sound and horizontal stripes.

I then yanked my Sony PSU, analog board and the little board that attached to the back of the CRT yoke. I replaced that with a working set (also with known good Sony PSU). I put the first motherboard. Still get the same artifacts and chimes of death. I then put in my second motherboard. Still get no sound and horizontal stripes.

I finally checked the voltage at the external floppy connector. With my first board (chimes of death and artifacts) I get 5.01v and 12.7v measurements. With my SimasiMac board, I get 4.90v and 12.6v.

Having tried everything I can think of, I am at a complete loss as to what to do next. I would therefore appreciate any help you kind souls could provide to get me back up and running again.

Dan, thank you for the reply. But as I wrote above in my original post, you can see that I swapped in a known-good WORKING motherboard and a known good WORKING analogboard. I also killed the HD and floppy to eliminate those variables. The only thing I didn't replace was the metal frame and plastic case, which have nothing to do with the problem.

and knowing how weird computers can be, Tried a different 'tube? As strange as it may be, that could be your problem.
I have seen stuff as simple as plugging in a USB Keychain, and the Network port goes out (still can't figure that one out...) and all oddities have happened in the electronic world. That's the only thing you can eliminate.
Just try the swap, and see if that is it.

While I didn't try to swap the CRT, I did change all the cables (I had a spare set of everything). Didn't solve the problem. And yes, I did plug and unplug several times, making sure each time the cables were securely locked in place.

you can see that I swapped in a known-good WORKING motherboard and a known good WORKING analogboard. I also killed the HD and floppy to eliminate those variables. The only thing I didn't replace was the metal frame and plastic case, which have nothing to do with the problem.

Heh, yeah, but did you solve the problem? That's why I always (if I can) start with a fully working unit and then swap in suspect bits one at a time (especially in a situation such as you describe here.) That way you've got no unknown loose ends over which to puzzle.

Sorry I can't actually help with the specific problem though . . .

dan k

PS: if I sound at all snippy here, don't mind me. I'm just jealous 'cause you've got one of those TS adapters . . .

i agree, you've eliminated everything in the machine except the tube. it could be going bad and drawing too much current. any tube from a compact mac will work i think. just make sure to discharge it first!

Guys I pretty much knew it was NOT the tube, but per your advice I pulled the know GOOD WORKING CRT out of my Mac 512 and put it in my SE/30. It did not help. Nothing changed. I've now pulled it out and put it back in my Mac 512 and the tube works fine (much to be relief -- I was worried I might kill it).

This is a known condition, called SimasiMac. Turn it on and let it sit there for up to 10 minutes... it may still boot. If not, check and clean connections between SIMMs (ROM-SIMM) and SIMM (ROM-SIMM) slots, and restart. If that doesn't help, check the battery. Replace it with a new one if voltage is low, and restart. If that doesn't work, you're gonna half to start replacing capacitors (C6 & C7). And there are still a couple more things you can do.

Thanks for the reply. I've not tried leaving it on for 10 full minutes, but I guess I can give that a try -- I didn't know "time" would cure SimasiMac. But what I can say is that I have reseated the ROM and RAM multiple times to ensure good contact. I though about using steel wool to clean the RAM & ROM contacts, but small parts of the steel wool would break off if I do that, and I might now be able to blow out all the particles even with compress air. I don't want a short, so I haven't used steel wool. But I can give a basic cleaning of the contacts with ethanol alcohol.

I've already checked the battery. It's a good one, testing at a solid 3.6v. I cleaned the battery contacts with steel wool (with the board upside down so the particles would drop down away from the board). So I know the battery contacts are good. I inserted and removed the battery multiple times, and I even tried booting without the battery in there at all. It didn't fix the horizontal lines problem.

As to the caps, I replaced them all a few months ago with good new electrolitics. I used hot glue to secure each cap (since they aren't SMD) to make sure they won't move and brake traces. Even so, I took a DMM last night and checked continuity on every lead from every cap to make sure the connections are good. I have an SE/30 motherboard schematic so I can see where the caps leads go to. No problems with broken traces from the caps.

I also soldered a 1k-ohm resistor (1.8W) across pins 7 & 15 of the sound chip as recommended on that repair mac website. I can't see why pulling up a pin on a SOUND chip would fix SimasiMac though. And the fact is, adding that resistor did not fix the horizontal lines problem.

I have also read about replacing the bourns chip (RP2), but I don't have one handy and I honestly do not see the logic behind that either. Looking at the schematic of that area, you can see that bourns chip is simply filtering the signals from the leftmost serial port and passing them through to another chip on the board. But if nothing is plugged into that particular serial port, the bourns chip is not used (from what I see) and therefore I cannot see how replacing the bourns chip would cure SimasiMac.

Still at it? Well, maybe now is the time to put together an actual working test platform, as per my original suggestion. Ever think that perhaps some of those parts you've assumed to be good are in fact not? I can't even count the number of times I've "assumed" parts were good (as in - "well, it worked last time I checked") only to find those parts somehow gone bad since "last time I checked".

Actually, your photo looks quite different from mine. You clearly have thick vertical lines on your Classic II screen, mixed with some garbage artifacts. From what I understand there are thick and thin versions of these vertical lines. I've never found a good resource that tells the difference between thick and thin though. However, you definitely have the THICK variety. On an SE/30 vertical lines (thick or thin, I wouldn't know) means somethiing RAM related. I am not having any RAM related problems, so that would be yet another area of difference. The suggestions made for your Classic II in that thread are basically to replace the motherboard caps, which I already did on my board and that didn't fix the problem. But I think in your case, the stripes mean something RAM related and the garbage artifacts may have something to do with the capacitors or a loose socketed chip.

I'm trying to fix and old SE/30 a friend of mine recovered from his basement.

Sorry to bother you all and JDW about this very old case but the picture JDW attached in the first append is very similar to the screen I'm getting on my SE/30 so I'm here to ask for help if someone may...

Previous history:
My SE/30 was dead so I started removing all the electrolytics , then did a complete cleanup with isopropilic alcool followed by water and soap.
Then some hours to dry in a owen at 50C.
Then replaced all the capacitors with equivalent SMD.
After powered the screen was black and chime of death.
No video sync at the J12 Connector.
I've replaced the 3 IC driving the sync UE8, UF8, UG8 (LS166,F393, F393).
This time screen light up but play the Chime of Death and shows a screen similar to JDW photo.

Unfortunately that site has been reworked and I couldn't find the append you were referring.

Replaced UC6 VRAM 41264 no change.
I tested all the memory multiplexer (UJ2,UJ3 and UI2,UI3 type 74F258) by removing the ROMSIMM and cheking with the oscilloscope the output signals.
The same with the video multiplexer (74F253) but I can't find any stuck lines......

JDW don't you, by chance, remember what was the issue for that case? Or someone can give me a suggestion about where to look at ?

Actually, I had two boards like that, and one had a socketed CPU, so I didn't want to throw that away. What I did was contact "TechKnight" in the 68kMLA forums. He had a look at the boards and found out that one one board the BOURNS filter that needed replacing. I bought some of those chips from "Trag" and had him ship them to TechKnight. TechKnight kindly did the fix.

But the other board with a soldered CPU had a bad CPU, according to TechKnight, so he removed the bad CPU and soldered in a socket for me. TechKnight also said he was experiencing issues with RAM. He couldn't remember exactly what he did to fix it, but I think it may have been leaked cap fluid that had eaten through a trace near the RAM SIMM slots and he fixed that.

In other words, if you clean and recap a board, it still may be dead due to other issues like a bad BOURNS filter and/or a trace eaten by leaked capacitor fluid.

I hope this info helps!

P.S. "Trag" is the person who used to sell complete cap replacement kits for the SE/30. I purchased all my cap kits from him and they worked great on boards that were cured only by a cap swap and cleaning.

very much thanks for the reply!
I'm late in replying you just because of the same, there is no mail back from the forum when someone append.
So today I just entered casually in the forum and, fantastic surprise, your explanations

I knew about TheTechKnight by reading the 68klma forum and I already checked the BOURNS filters by following a youtube video from him:https://youtu.be/kXml_0HJ2pM?t=688
Unfortunately, they seem to be ok, but I'll check them again.... just to be sure!

What you tell is interesting in the fact that, in your board, TheTechKnight found also a different fault once the BOURNS filters were replaced.
And also interesting that (may be)it was something relate to the memory.

I ipotize the video corruption i'm experiencing is just a secondary issue and there is a different fault who is causing the Chime Of Death...... which could be related to the memory.

I've already swapped everything was swappable: RAM,ROMSIMM,VIDEO ROM
with a working board and nothing changed.

In the meantime I've replaced the video and ram mux(type 74F258 and 74F253) just to be sure.... but the previous oscilloscope measurements were correct..... the mux were good.

I'm quite out of ideas apart.... sending the board to TheTechKnight, ehehehe!

But in the begin all that was to help a friend to raise little money while moving in a different city....

Anyway I don't surrend for now, but I'm not prepared to find a fault caused by the CPU itself or similar ICs: GLU, Copropcessor and so on.

I will keep you informed if I find something useful and I'll try to submit also in 68kmla forum; may be someone or thetechkinght himself may give suggestions.

Many thanks again for the kind help, your hints were precious.
Have all the best

I actually received an email notification about your reply today from this forum. It was in my SPAM folder, but I found it!

The only other thing I could suggest is that you get your digital multimeter, put it in "Continuity Check" mode (you should hear a BEEP when you touch the meter's probes together), and then use a schematic to check for broken traces. It sounds like that is the only thing you haven't yet tried. I will send you a PM with the link to the schematics.

Since we are now dwelling on the topic of the SE/30, you might find this discussion interesting:

I can't manage to register a new account on 68kmla so this morning I wrote to the administrator to let me in.
I would like to append there a description of the case and then I hope TechKnight may have a look.
I that doesn't happen I will try to disturb him via PM.

Yesterday evening I did other checks with the DMM but still nothing..... bah!!
Meanwhile I'm reading your Odyssey with the Micron Xceed

You need to buzz out and verify connections to every single pin in the RAM sockets, as well as make sure you have good RAM.

If the RAM socket connections check OK (usually the first socket, closest to the cap that breaks, and the lines to the IC and resistor pack next to it.), Then change out all of the 74F253 muxes. If its not a broken connection, then its the muxes.

Running without the ROM will only tell you so much because the Multiplexer's control line actually never toggles so you cannot verify the truth table when the line is being driven in its opposite state. So, I always just change them.

the 253 ICs usually fail because the RAM that was used wasn't entirely compatible, or the RAM failed itself which overloads the muxes.

If the muxes AND 30-pin SIMM traces check out, the last thing is the PAL right next to the main oscillator crystal. I have only ever seen it go bad once, and it contains the read/write timing for the RAM bank. If its bad, the RAM will be stuck always in read mode, or write mode.

I already changed the F253 Muxes and also the F258.
Apart from the complete cleaning of the board I removed and cleaned also the underside of RP1 and UD1 near the SIMM slots and checked just the lines from UD1 to the SIMMs.

I checked just some of the SIMMs control lines and they were ok but I need to do a systematic job.

A strange finding while testing the address lines with the oscilloscope was that the A16 address line (measurable on pin 110 of J13 connector) was active showing a square wave just few seconds after the boot then goes LOW and remain in this state forever.

May be the processor is just looping in a sector of memory where this line is always low but at the begin I thought to have found the culprit.

" the last thing is the PAL right next to the main oscillator crystal. I have only ever seen it go bad once, and it contains the read/write timing for the RAM bank. If its bad, the RAM will be stuck always in read mode, or write mode"

Is it UK4 ? and then, is there a line I can measure to assess this kind of issue ?

I will measure (buzz) the SIMM lines and keep you informed.
Again many many thanks for the patience and the kind help.
Have all the best.

I checked the continuity of all the RAM pins (just for the SIMM banks 1 and 2) and everything was fine.

Then I scoped the pins of UK4, the RTC chip near the 32 Khz quartz, and something was strange.
The signal coming from pin 1 (1 Hz RTC) was constantly HIGH, no switch to LOW level.

So it seems I need to change this IC and for the moment I rescued one of this chip from an old motherboard but I still
have to desolder the failing one from the board and resolder the salvaged one.
Unfortunately during the week I can't work on that so next update will come with the weekend.

I'll keep You all informed about the evolutions, every suggestion is very welcome.

With regard to UK4 (3440042-B Real Time Clock), located near the battery holder and XTAL "Y1":

1. Is pin-8 getting constant 5V?
2. Is pin-4 getting a solid Ground connection?
3. Did you check pins 2 & 3 to confirm if the XTAL is oscillating at 32kHz?
4. Pin-5 is Chip Select. Does it ever get grounded when the motherboard is fully connected?
5. Are all the PCB traces leading to the chip good? (You can check Apple and BOMARC schematics to confirm traces lead to/from that 8-pin RTC chip.)

3. Did you check pins 2 & 3 to confirm if the XTAL is oscillating at 32kHz?
Yes

4. Pin-5 is Chip Select. Does it ever get grounded when the motherboard is fully connected?
No, it goes HIGH and there remain steady

5. Are all the PCB traces leading to the chip good? (You can check Apple and BOMARC schematics to confirm traces lead to/from that 8-pin RTC chip.)
Yes, buzzed all the pins between UK4 and UK12.

The only discrepancy is the RTC-1HZ signal, pin 1 of UK4.
It remains in HIGH state.
The same pin in a working board produce a 1Hz square wave.

I think I need to change it....
I have desoldered one of that chip from a broken board where the battery exploded and corroded everyting around and superficially the pins of the IC.
So I can't be sure the chip survived, I wonder if it is sold by someone like farnell, digikey or so....

I did an extensive Google search for that RTC part number and also for similar real time clock chips that are in the eight pin package size, but I couldn't find a drop in replacement for it. Because I can't even find a data sheet for that shit, I don't know exactly what the operation should be, but usually the CS chip select input, when brought to ground, would allow data to flow from that chip.

If you have a breadboard and either a function generator or the required Crystal and capacitors need it, you could test your replacement chip before you solder it jnto the motherboard, assuming you also have a 5V power supply. That's what I would do.

I believe the CS line should be anyway HIGH, at least, this is the value I found in the working MB.

Also, the symbol for the RTC pin-5 has a little circle on it, meaning that the value coming from UK12 will be
inverted before being used in the RTC.
This means that a HIGH value will be "negated" becoming internally LOW and the RTC should be enabled.

The suggestion of testing the recovered RTC before going through the hassle of desoldering the old is very much appropriate.

I have a function generator (a good old HP 8116A 50MHz), the power supply and the breadboards but I doubt i can simply attach the function generator to the pin 2 and 3.
Firstly, I imagine the two pins are in different phases, (180 degrees difference) because they attach to the opposite side of the quartz.
So the generator output should go to one pin (ex: the pin-2) and also to an inverter, like a transistor in common emitter configuration,
whose collector-output would go to the other pin (ex: pin-3).

But then, if the RTC is expecting to drive a quartz I suppose it wouldn't accept to work easily with an external driver.

Alternatively I could dismount the 32Khz quartz from the old (not working) MotherBoard and use it on the testing breadboard.....

But definitively is better if I try to test it before going on.
This weekend I'll continue on that and I'll report.

I couldn't test the RTC on a breadboard because the quartz from the broken board I was thinking to use was simply missing...
In that board the battery exploded and the electrolyte eat away also the legs of the quartz.

So I desoldered the RTC from the board to be fixed, mounted a 8 pin socket and pushed on the "new" RTC recovered from the exploded battery board.

Reconnect all, power on and the result is........... Nothing different!!!

oooouufffff.....These are the days of our lives (The Queen)
where you may find your inner buddha or start swearing.
;-D
I just measured the pin 1 with the scope and, no surprise, was steady HIGH instead of 1Hz wave.

May be the "new" RTC is broke the same way of the old.

So I plugged out the RTC from his socket and probed again the pin 1.
The level was a steady HIGH without the RTC in the socket.

That pin goes straight to UK 12.... who, in turn, could be bad, but at this point.....
I'm ready to surrend.
I've spent too much time and mostly I haven't any idea about where to look and I made no
advance after all this time.
So it's time to follow Mike's suggestion: scrap that board and pass on.

In the end has been a nice experience and, from 2 board, at least one worked.

James, Mike have all my gratitude for your kind help and precious suggestions, your appends in the forums and youtube videos have been my preferred readings for a long while.

I hate to say a silly logic board defeated me but age, exploding batteries and leaked capacitor fluid can result in an unrepairable board (something even TechKnight cannot repair). And on that note, I leave you with some more Queen:

Navigation

Announcements

This page, the entire Applefritter site, and all subsites of are copyright 1999-2999 by Tom Owad unless otherwise noted. All rights reserved. Apple, the Apple logo, Macintosh, Mac, MacOS, MacBook, iMac, and Mac Pro are trademarks of Apple Computer, Inc. LEGO®is a trademark of the LEGO Group of companies which does not sponsor, authorize or endorse this site (the feeling's mutual).